So here's a real quick tutorial on how I did the vegetation in the recent posts to the Italy WIP thread, if you haven't seen it you can view it here: http://www.beamng.com/threads/italy-progress.24505/#post-379088 This is an enormous improvement to the vegetation. So far I've only done quick mockups but it's really impressive. Before I start I'll tell you how it works. Essentially we take one object (our mesh) and tell it to get new normals cast from a second object. So instead of your face pointing at 90 degrees it points away from the second object, labeled "target" in this messy pic: With this you can make your polygons point one way but receive light from another, this is incredibly useful because in doing so you can make "smooth" groups of polies. With vegetation we're using flat panels and trying to represent dense clusters of hundreds of thousands of complex tiny leaves and twigs, this lets us make 10 disconnected polygons pointing all over the place behave like a single cluster of complex objects. First up, create a vegetation clump (here I've made an ugly bunch of squares but anything will work) and set auto-smooth to enabled in the data panel: Second, create any object, I used an arrow (the only thing we'll be using is it's origin point). I find it works best if you position it behind the object: Next add a normal edit modifier: Now set a target for the modifier: So it's working, keep in mind you can also choose how powerful the effect is, I've set it to 100%. Now make a duplicate object in the same location and hit apply. You can now use this and make a heap of copies to build a tree: Depending on the shape, texture and desired result you can leave it there or duplicate your final result (so you can still make changes later) and repeat the process to smooth out the tree even more. Here I've set it to a low amount to subtly smooth it some more: You can go right up to just having a ball: Anyhow, here's what it can do, the end result is on the left and without any of this you'll get what's on the right: I've also attached the blend file so you can see how it works. I hope this helps, good luck modding
